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-   -   CIS Guru Question (http://forums.pelicanparts.com/porsche-911-technical-forum/376614-cis-guru-question.html)

Gunter 11-10-2007 10:55 AM

Just to clarify:
We have to differentiate between Euro and US.
My info about US models comes from Boschusa; I have no info on Euros.
If you have a US '78 Targa, Boschusa states that your FD should be 0 438 100 031 like you said.
But the FD for US '80-'83, according to Boschusa, should be 0 438 100 077.

I have several complete US CIS systems: '78, '80, '82 and the numbers from Boschusa correspond to the actual numbers on my 3 CIS systems.

Pkaaso 11-10-2007 12:22 PM

Well I am fairly satisfied that the .031 F.D. was used on the 78-79 US and Euro.

Anyone disagree???

Now for the air flow meter.

If I haven't mentioned it lately.... THIS BOARD ROCKS!!!!!! You guys are the best!

Jim Williams 11-10-2007 01:08 PM

Quote:

Originally Posted by munsonbw (Post 3580381)
I was afraid that I was going to have to get the number off the plate itself... but found the number on the housing.

Air metering housing = 0438 120 143
WUR = 0438 140

Jim, this doesn't jive with what you were expecting. I'll have to dig tonight and see what this means. I just took a lunch break from being arms deep in a rebuild of the engine.

Ben,

The number in your post for the WUR is an incomplete number. There will be three more digits stamped into the WUR body: 0438 140 xxx. This sometimes requires a very close look to make out the last 3 digits.

boyt911sc 11-10-2007 01:16 PM

Quote:

Originally Posted by Gunter (Post 3580473)
Just to clarify:
But the FD for US '80-'83, according to Boschusa, should be 0 438 100 077.

I have several complete US CIS systems: '78, '80, '82 and the numbers from Boschusa correspond to the actual numbers on my 3 CIS systems.

Gunter,

The reference Bosch table I used does not tell me whether US or RoW car. So your info should be the right one unless someone has other idea. Thanks.

Tony

munsonbw 11-10-2007 01:54 PM

Ok here it all is for a '81 ROW car. 39mm ports and runners:
Air metering housing = 0438 120 143
WUR = 0438 140 089
FD xxx xxx 097

Since we have the attention of the CIS gurus, any idea what this is? ~80mm long with a 5-7mm rubber plug on the end. It was laying on the back of my CIS airbox. Amazing it hasn't been lost yet.


http://forums.pelicanparts.com/uploa...1194735253.jpg

Jim Williams 11-10-2007 02:56 PM

Quote:

Originally Posted by munsonbw (Post 3580691)
Ok here it all is for a '81 ROW car. 39mm ports and runners:
Air metering housing = 0438 120 143
WUR = 0438 140 089
FD xxx xxx 097

Since we have the attention of the CIS gurus, any idea what this is? ~80mm long with a 5-7mm rubber plug on the end. It was laying on the back of my CIS airbox. Amazing it hasn't been lost yet.

Ben,

That fits into the hole in the airflow sensor housing through which you access the mixture setting for the Fuel Distributor. It doesn't really do much except to keep to keep trash out of the allen adjuster. It is a small miracle it is still with the engine.

Gunter 11-11-2007 06:30 AM

Wunderbar.
Ben: Bosch used that plug for all their K-Jetronic FD's; like Porsche, Volvo etc.
I like the plug and to make sure it doesn't get lost, I have a short small key chain trough the eye and around one of the fuel lines.
A little Vaseline helps to get it in. :rolleyes:

Gunter 11-11-2007 06:59 AM

[QUOTE=Pkaaso;3580586]Well I am fairly satisfied that the .031 F.D. was used on the 78-79 US and Euro.
QUOTE]

Paul:
Unless you go with larger P/C's and a higher lift cam like a 964, you are maxed out with your set-up.
The US FD for '78-'79 (Non-Lambda) is good for slightly better delivery but a bored-out throttle body is additional cost/work for no real gain.
I suggest that you make the best of what you have; SSI's will add about 10-15 HP depending on muffler.
Concentrate on recurving your distributor, Steve Weiner will do it.

Two years ago I bought an '82 SC engine and build a SS 3.2 with '78 CIS.
98mm P/C's, 964 cam, Ported heads to 39mm to mate with the larger runners from the '78 CIS.
With the SSI's, I added about 40 horses to the stock 180 HP.
I use a '78 ignition distributor.
Cost was about $5k

Pkaaso 11-11-2007 06:34 PM

Gunter
I an running the WEB Cams, 21/20 seems to have a very smooth / even power band.

So, the Luftmengenmusser (air flow meter/throttle body) is the debate.

Using the chart from MBEngineering (thank you very much for the contribution)
I understand this would be ROW/Euro part numbers.

78 - 81 used 0438 120 070
81 - 82 used 0438 120 143

Question:
1.What is the difference? i.e. size of bores, geomitry of mechanism, etc...?
2. Did the US and ROW use the same parts year for year?
3. Is there another year/model's "Air Flow Meter" that may function more favorably?

I will check what I have but I suspect is will be the x.143

BTW The Aircraft Carrier (now museum) "Midway" was an incredable experience. We slept in the enlisted man's bunks. SMALL, SMALL, SMALL. Ate the mess chow and toured the ship, did flight simulators and got to see 1940's engineering. Ship completed in 1945, was built in 18 months by huge number of the ladies, and lunched the most sorties in Desert Shield amoung the 4 other newer Air Craft Carriers in the gulf at that time. Retired in 92'. WONDERFUL Experience.

Thanks All,
Paul

Pkaaso 11-12-2007 09:16 AM

So, the air flow meter I have on my 81' is 0 438 120 149
This should be the U.S. one correct for the year.

*MB*,
Any chance you could get the column that shows the "Air Flow Meter" Eruo part numbers, please?

*boyt911sc* Maybe you have the U.S. numbers for the air flow?

Anyone else have the part numbers for the U.S. "Air Flow Meters?" I'd like to comare with the Euro.

I also have a U.S. 74' that has 0 438 120 004 air flow meter. But I can't find the throtle body numbers.

Anyone know where the throttle body numbers are?

Thanks,
Paul

hmd 11-12-2007 03:35 PM

Can any one tell me why the Euro SC with 9.8 C/R made less power than the Euro C3 with 8.5 C/R?

Are there differences in these two CIS components?

450knotOffice 11-12-2007 04:25 PM

I believe it was due to cam timing issues and other such "tuning" factors. I read about it recently, but my memory is fading on this issue.

I was just at Paul's shop and he's getting a big lean-out above 4,000 RPM. His fuel pressures are good, so the idea is that the Air Flow Meter he currently has isn't properly calibrated to the amount of air coming into the engine at higher revs and isn't commanding the FD to meter enough fuel in (that's the basic theory, anyway).

So, all ideas are still welcome guys.

boyt911sc 11-12-2007 04:25 PM

Quote:

Originally Posted by Pkaaso (Post 3583588)
*boyt911sc* Maybe you have the U.S. numbers for the air flow?

Anyone else have the part numbers for the U.S. "Air Flow Meters?" I'd like to comare with the Euro.

I also have a U.S. 74' that has 0 438 120 004 air flow meter. But I can't find the throtle body numbers.

Paul,

The reference table that I have does not tell me whether it's US or EURO. The AFMS for '74 is -004 and for '81-'83 is -149 from this Bosch Reference table same as you have. I would suggest that you PM Gunter for this info.

Tony

Pkaaso 11-12-2007 06:04 PM

Boy911sc,
Thanks for the info.

What number does it give you for the 78-79 U.S. AFMS.

Gunter 11-13-2007 07:22 AM

To be clear, Paul:
Do you have a complete US '78 CIS sitting on top of an '81 US 3.0 liter engine?
What is the cam timing on the 20/21?
Carbs would get you richer at higher RPM's.
Knowing that the CIS leans out at higher RPM's, I keep my US '78 CIS mixture on the rich side.
I cannot see how a slightly larger bored throttle body would get you a richer mixture at higher RPM's.
Forget about the '74 AFM

Pkaaso 11-13-2007 07:34 PM

No Gunter, not a complete system.

I have the 81' that I replaced the following:

1. runners/airbox with 78-79 large (heads ported to match)
2. FD with the .031
3. WUR .045

Cam timing: 1.9 - 2mm.
I have the CO mixture set fairly rich at idle.

I'm not implying that the larger throttle body would richen the top end. I think problem is the AFM. I may have an extra 78-79 AFM (if I can find it) that I will install and test again on the smog dyno.

Thanks,
Paul

Gunter 11-14-2007 06:39 AM

Quote:

Originally Posted by Pkaaso (Post 3586937)
No Gunter, not a complete system.

I have the 81' that I replaced the following:
1. runners/airbox with 78-79 large (heads ported to match)
2. FD with the .031
3. WUR .045

WELL, THAT ALMOST SOUNDS LIKE A COMPLETE '78 CIS TO ME.
WHAT IS MISSING?
BY AFM, DO YOU MEAN THE AIR SENSOR PLATE THAT ACTUATES THE PLUNGER IN THE FD?
WHY NOT MEASURE THE PLATE SIZE IN BOTH HOUSINGS TO SEE IF THERE IS A DIFFERENCE?

Cam timing: 1.9 - 2mm.

ARE YOU SURE THAT IS THE RIGHT TIMING FOR 20/21 WITH CIS AND 95 mm P/C's?
DID CAMGRINDER RECOMMEND THIS?

I have the CO mixture set fairly rich at idle.

I'm not implying that the larger throttle body would richen the top end. I think problem is the AFM. I may have an extra 78-79 AFM (if I can find it) that I will install and test again on the smog dyno.

Thanks,
Paul

O.K.

Pkaaso 11-14-2007 05:39 PM

Gunter,
Yes, I am calling the metering plate housing the AFM (Air Flow Meter) because I have heard the term serveral here. The newer cars call them AFM or Air Mass Sensors.

I haven't found the other 79' CIS system yet. It's lost in Jon's garage (450knotoffice) can attest to this nightmare of a parts heaven.

I am still hoping someone can enlighten me on the diffence of the AFM's.

I will call WEB cams tomorrow and ask. The 2mm was recomended from a long time builder but we did not set for the cam especially.

Thanks,
Paul

Jim Williams 11-15-2007 06:55 AM

Hi Mike at MBE,

Would it be possible for you to post a photo of the right hand side of your chart that has the heading "911.911S 2,7 l Hub..."?

Jim Williams 11-17-2007 08:01 AM

Paul,

I have some data from measurements I made on an '80 US air flow meter (AFM) and an '80 RoW AFM.

The US one, an xxx.118 has a 76 mm plate, and the RoW, an xxx.070, has an 80 mm plate. There are also some differences in the venturi contours. I will post sketches of the venturies when I can draw them out and scan them. I thought this might have some bearing on your mixture problems.

Ben,

Can you make some measurements on your xxx.143 AFM (I used a vernier caliper to make mine), including the sensor plate, and post them? I will plan on posting all this info on my website when I get it together.


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